The present invention relates generally to adjustable beds and more specifically to a bed having an improved adjustable foot section.
There are many known bed designs that have adjustable foot sections. On beds that convert from a planar bed configuration to an upright chair configuration, the foot section is generally shortened as the foot section rotates from a horizontal to a vertical position. There are also beds having adjustable lengths wherein an attendant physically repositions the head or foot section of the bed to the desired length. These designs include a sliding telescopic foot section as well as a folding foot section equivalent to a "lazy boy" design. It is also known to deflate the foot section of the mattress when converting from a bed to a chair. For short occupants, there exists a need for adjustment of the foot prop or board in the chair position shorter than that attended by adjusting the length of the foot section.
The ability to adjust the length of the foot section independent of converting from a bed to a chair is also important. This would assist in maneuvering the bed in a confined locations during patient transport. It also allows the bed length to be customized to a patient's size. If a foot prop is provided at the end of the foot section, the adjustment of the foot section and the prop would prevent patient migration across the support surface of the bed. It would also provide support for the feet to thereby improve the patient's feeling of security. It could also be used in the prevention of peripheral neuropathy ("foot drop"). Positioning the end of the mattress relative to the patient substantially increases the ability to provide heel management. Heel management is wherein the heel is supported by the thigh and the calf and the heel has reduced pressure contact with the mattress.
Certain individuals who are confined to bed for an extended period of time are vulnerable to skin breakdown on the back of the heel. Protection of the skin in this area is important if initial indications of tissue failure are observed. If the breakdown process has progressed to a point of ulceration, protection of the heel area of the patient is essential to healing.
Reducing or eliminating the time an individual spends in a supine position will protect the heel area, although it may increase the risk of skin failure on other areas of the foot and body. The current practice for protecting the heel area of a patient while in the supine position utilizes foot support to reduce or eliminate pressure and shear on the back of the heel. Such support is often provided by placing an ordinary pillow or folded towel under a calf area of the patient's legs. Several different foam boot designs are known that strap to the leg or foot to reduce the effects of heel pressure. In addition, a conventional mattress is known in which removable sections are provided in a foot area.
All of these conventional support methods require a caretaker to add or remove components from the bed in order to control pressure on the heels of the patient. Components which are removed from the bed have the potential to get lost or mislaid. Components that are added to the bed provide an extra cost associated with the purchasing, cleaning, and disposal of the added components. There is also a cost in time for the caregiver who must go through multiple steps to initiate and maintain the support of the device.
The present invention provides a bed capable of achieving these goals. The bed includes a deck having a foot section of a variable length along the plane of the foot section. A foot prop is mounted to a first end of the foot section and extends transverse to the plane of the foot section. A mattress on the deck has a foot portion of adjustable length along the plane of the foot portion and variable thickness transverse to the plane of the foot portion. A heel portion of the foot portion of the mattress adjacent the foot prop has a thickness variable independent of the thickness of the remainder of the foot portion. The foot portion of the mattress includes a plurality of variable length elements separated by a plurality of variable thickness elements. The variable length elements are connected to operate simultaneously and the variable thickness elements are connected to operate simultaneously and both operate independent of the heel portion. Preferably, the heel portion, the variable length elements and the variable thickness elements each include one or more bladders which are inflatable and deflatable.
To achieve a chair bed, the foot section of the deck is pivotally mounted to the remainder of the deck. A first actuator varies the length of the foot section of the deck, a second actuator pivots the foot section of the deck and a third actuator varies the length of the foot portion of the mattress. A fourth actuator varies the thickness of the heel portion of the mattress and a fifth actuator varies the thickness of the remainder of the foot portion of the mattress. The second actuator is deactivated when it encounters a predetermined resistance. Preferably, this is during rotation down.
A control system includes an angle sensor and a length sensor connected to the foot section of the deck. Also, a foot prop sensor is connected to the foot section of the deck. As the length sensor senses the position of the end of the bed or it's length, the appropriate inflation or deflation of the bladders is made to adjust the length of the foot portion of the mattress. The angle sensor cooperates with the foot prop sensor and the control system so that the foot section cannot pivot to an angle which will allow egress form the end of the bed without removal of the foot prop. This is preferably in the range of 65.degree. to 90.degree. from horizontal.
The foot prop has at least one foot support surface and means are provided for mounting the foot support surface to the foot section of the deck at different distances from the end of the foot section. The mounting means includes one or a pair of sockets spaced along the length of the foot section to receive the foot prop. The foot prop may include a rod received in the sockets. The rod may be mounted asymmetrical with respect to a pair of opposed foot support surfaces. By rotating the foot prop 180.degree., the foot prop can be mounted in the same socket and achieve an adjustment. Alternatively, the rod may be symmetrically located and the distance adjusted by selecting one of a pair of sockets spaced along the length of the second foot section. The foot prop provides support from the horizontal to a chair position up to an egress range of foot section angle.
Another method of shortening the length of the foot support surface beyond that which is produced by shortening the foot section of the deck is to not shorten nor thin the mattress foot portion when the foot section of the deck is shortened. The foot portion of the mattress can then be folded up the support surface of the foot prop. This decreases the distance of the foot support surface by the thickness of the mattress foot section.
The structure which allows adjustability of the length of the foot section of the deck includes a first section connected to the remainder of the deck and a second section movable relative thereto. Telescopic guides connect the first and second sections and the actuator also connects the first and second sections. Preferably, the actuator is between a pair of spaced telescopic guides connected to the first and second sections. Also, preferably, the telescopic guides includes three telescopic elements. The second foot section has a generally U-shaped cross section encompassing part of the top and lateral sides of the first section. The first section is a trapezoid having a large and small oppose surfaces and the large surface is the top of the first foot section. The foot section of the deck has a width smaller than the width of the remainder of the deck and the foot prop is mounted to lateral extensions of the foot section. The width of the foot section with the lateral extensions is substantially equal to the width of the remainder of the deck. Bumpers are also mounted to the lateral extensions.
To size a support surface of the bed to an occupant and provide heel management, the bed may be used in the following method. The length of the foot section with a foot prop thereon is adjusted until the foot prop is immediately adjacent the foot of an occupant on the support surface. The thickness of a portion of the support surface of the mattress below the heel of the occupant is reduced. The length of the foot section of the deck and the foot portion of the mattress are adjusted simultaneously. The foot section of the deck is adjusted using the first actuator, the foot portion of the mattress is adjusted using a second actuator and the thickness of one of the portions of the mattress foot portion is reduced using a third actuator.
A mattress includes a foot portion and a body portion within a ticking. The foot portion is secured to the ticking as an adjustable length. The foot section may either be corrugated foam of adjustable length or a plurality of bladders which are inflatable and deflatable to adjust the length. The bladders need not be secured to the ticking. The ticking includes at least one slot and the foot section includes a flap secured thereto and extends into the slot to secure the foot section to the ticking. The ticking includes an interior pocket and the slot is in the interior pocket. Magnets secured to the ticking for securing the mattress to the bed may also be provided in the pockets. A plate is also mounted to the foam displaced from the flat and straps are secured to the plate and join the foot section to the foot portion of the mattress to the body portion of the mattress. A slip cover is provided encompassing the foot section to allow easy movement of the foot portion relative to the ticking.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.